A transmission is a machine that provides controlled application of a vehicle engine power. In other words, the vehicle transmission adapts an output of an internal combustion engine to the driven wheels by reducing a high engine speed to a slower speed, which allows the vehicle to start, stop, and move at a slower speed.
FIG. 1 illustrates a schematic view of a cooling system 100 for a vehicle used for controlling the temperature of an automatic transmission 120. The system 100 includes a radiator 104 and an engine 106. The radiator 104 is in fluid communication with the engine 106 and is used to control the engine's temperature and cool cooling fluid circulating between the radiator 104 and the engine 106. The system 100 includes a thermostat 108 in fluid communication between the radiator 104 and the engine 106. The thermostat 108 is configured to maintain a temperature of the engine 106 near its optimum operating temperature by regulating the flow of cooling fluid to the engine 106.
The system 100 also includes a heater core 110 that is also in fluid communication with the engine 106. The heater core 110 is a radiator-like device used to heat an interior of the vehicle. Hot coolant from the engine 106 is passed through a winding tube of the heater core 110 before returning to the engine 106, causing a heat exchange between the hot coolant and the air in the interior of the vehicle.
The system 100 also includes an oil cooler 112 used to provide additional cooling to the engine oil before it flows back to the engine 106. The hot engine 106 transfers heat to the oil cooler 112 by way of the heater core 110 which cools the engine oil and transfers it back to the engine 106.
In some examples, the system 10 also includes a heat exchanger 114, such as but not limited to, an ATWU heat exchanger. The heat exchanger 114 is designed to allow heat transfer between two fluids, one being the fluid received from the heater core 110 and transferred to the oil cooler 112.
The system 100 also includes a first bypass valve 116, such as, but not limited to, an automatic transmission warm-up unit (ATWU) bypass valve. The ATWU bypass valve 116 is in fluid communication with the heater core 110, a heat exchanger 114, the oil cooler 112, and the engine 106. The heater core 110 is in fluid communication with the heat exchanger 114 which receives engine oil from the heater core 110 and transmits the fluid to the oil cooler 112; however, in some examples, the ATWU bypass valve 116 bypasses the heat exchanger 114 and the oil cooler 112 and transmits the engine oil to the engine 106.
The system 100 may also include an electronic control unit (ECU) 118 that controls one or more electrical systems or subsystems of the vehicle. The ECU 118 receives temperature sensor data from one or more temperature sensors outside air, engine coolant, and transmission oil. The ECU 118 controls a series of actuator on the internal combustion engine to ensure that the engine 106 works at its optimal performance. In addition, the ECU 118 provides electrical ground bypass for the first bypass valve 116.
As shown, the heat exchanger 114 is designed to allow heat transfer between fluids from the engine 106 (i.e., engine oil) and the automatic transmission 120 (i.e., transmission fluid). In some examples, the system 100 includes an auxiliary cooler 122 for providing additional cooling to the automatic transmission 120 when needed. An auxiliary cooler bypass valve 124 allows the transmission fluid to bypass the auxiliary cooler 122 when no additional cooling is needed.
The system 100 also includes a transmission control unit (TCU) 126 in communication with the automatic transmission 120 and the ECU 118. The TCU 126 is commonly used for controlling the operation of an automatic transmission of a vehicle. As such, the TCU 126 receives sensor data from the sensors and ECU data from the ECU 118, and based on the received data, the TCU 126 determines how and when to change gears in the vehicle for optimum performance and fuel economy. Generally, the TCU 126 is places outside the transmission 120 to prevent the TCU 126 from being exposed to the high heat of the transmission 120, which may reach 140 degrees Celsius. The TCU includes circuitry, which may malfunction when exposed to the high temperatures of the transmission 120. This limitation has generally lead to transmissions being designed such that the TCU 126 is located outside the automatic transmission, as shown. This presents limitations with regard to packaging, and where to place the TCU within the engine compartment.